drm/i915/uapi: add probed_cpu_visible_size

drm/i915/uapi: add probed_cpu_visible_size

Userspace wants to know the size of CPU visible portion of device
local-memory, and on small BAR devices the probed_size is no longer
enough. In Vulkan, for example, it would like to know the size in bytes
for CPU visible VkMemoryHeap. We already track the io_size for each
region, so plumb that through to the region query.

v2: Drop the ( -1 = unknown ) stuff, which is confusing since nothing
can currently ever return such a value.

Testcase: igt@i915_query@query-regions-sanity-check
Signed-off-by: Matthew Auld <[email protected]>
Cc: Thomas Hellström <[email protected]>
Cc: Lionel Landwerlin <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Cc: Jon Bloomfield <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Jordan Justen <[email protected]>
Cc: Kenneth Graunke <[email protected]>
Cc: Akeem G Abodunrin <[email protected]>
Acked-by: Nirmoy Das <[email protected]>
Reviewed-by: Thomas Hellström <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]